Fe, O percentage = 70, 30 divided by relative atomic mass = /56, /16 = 1.25, 1.875 (I think people rounded their answers here or on the step below) divided by the smallest = 1,1.5 times by 2 to get a whole number = 2,3 (Fe2O3)
actually, if you do the ratio upside down, but all the rest of your working is correct, you will only lose one mark.
If you do the working out upside down then the rest of your working will be incorrect as it relies on how you set it out. marks are only awarded if you do not simplify or get the right awnser so you will get the mark for Mass/MR. Mr/Mass is not awarded marks as it is the incorrect way to work it out.
If you do the working out upside down then the rest of your working will be incorrect as it relies on how you set it out. marks are only awarded if you do not simplify or get the right awnser so you will get the mark for Mass/MR. Mr/Mass is not awarded marks as it is the incorrect way to work it out.